Fix deprecation error

[freezy]

mcrypt_create_iv() is deprecated in PHP 7.1 and removed in PHP 7.2. The latter is less severe because there are fallbacks, but 7.1 crashes with deprecation errors.

This checks for random_bytes() first and prefers it over mcrypt_create_iv().

[wohali]

Thanks.

Hm, the sources/oauth library is an upstream library. Should check to see whether or not there is a new version rather than patching their code first.

[freezy]

Oh, right.

By the way, IPS 4.3 will contain a full-featured OAuth2 server. Are you going to keep this maintained or rather add a way to migrate to their version?

[wohali]

I will probably drop support for this when 4.3 releases. I can look into offering a migration path but it will entirely depend on how 4.3 implements their support.

I'm rather busy with non-software projects these days, so I won't have time to look at this until 4.3 is formally released.

[freezy]

Sure, I might be able to contribute to a user migration feature, but I haven't seen their model neither.

[wohali]

Any luck on checking the upstream project? I can merge this if necessary, but I'd rather keep that sub-directory a pristine import.